Quasi-discrete resonances observed in photoionization to the [formula omitted] state of the CS 2+ molecule

• Published in: Chemical physics letters Vol. 285; no. 5; pp. 373 - 378
• Main Authors: Karawajczyk, A, Erman, P, Rachlew, E, Stankiewicz, M, Yoshiki Franzén, K
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1998
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/S0009-2614(98)00078-5

We report total and dispersed fluorescence studies of the A 2Π u – X 2Π g emission system in the CS 2 + molecule. The single-electron Rydberg series converging to the B 2Σ u + and C 2Σ g + states have been observed in the undispersed fluorescence spectrum as pronounced window-type resonances. Autoionization from these states gives rise to a non-Franck–Condon distribution of the vibrational population of the final CS 2 +(A 2Π u) state. It is shown that the vibrational branching ratios primarily depend on the l-quantum number of the Rydberg state and they may give information about perturbations of the Rydberg states. At 20–21.5 eV excitation energy the undispersed fluorescence spectrum reveals a previously unobserved structure which has been tentatively attributed to a 2 π u −1 shape resonance. No deviations of the branching ratio have been found in agreement with the predictions of multichannel theory.